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Can anybody point to me to where I can find the following information. 1. Diameter of the fuel rail. 2. Distances from a referenced end to the center of each injector all the way to the other end. 3. Good pics of both an actual injector cross section. 4. A good description of acutal injector functioning. I would like this info to help in further developing a hypothesis that I mentioned HERE TIA for your help and input  ,Larry |
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Larry, Hutch has this info on his webshots pertaining injectors. I didn't know if you knew it was there or not. Hope this helps! Rob |
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movintons, Thanks, I'll need time to digest that. Another question: Are the injectors indexed so they fit into the head in only one orientation or are the openings to the HP and fuel sides symmetric around the long axis of the injector? Larry |
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Larry, I am not sure if they are indexed but they only go in one way because of the holddown which is attached to the injector. The injector may be able to turn slightly till tight. If it can it is very little but I would guess it has some kind of index. Maybe someone with a LL #8 could look at it and chime in. Rob |
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Larry, Your heading in the right direction Man. Dynamics, fuel rail, etc. Don~ cross-flushing!! is a good part of the answer |
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I know that the engine used in the study listed below is not the same as ours but it discusses the effects of rail harmonics upon the fuelling of injectors. Ken http://www.jat.co.kr/eda/acsl/rail.html |
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O.K. I ruined my eyes and read the patent info for the LL injector shown HERE and think I now understand basically how these work at least at a novice level. Barrel w/o Plunger (big thanks to Hutch for the great pic) picture actually shows the hole on the outside of the barrel that is open to the to the fuel rail and is shown as passage 71 in the top of this Patent Picture . This passage not only goes to the inner portion of the barrel thru a check valve to fill the HP fuel pump chamber, but also goes up and then into the inner portion of the barrel thru what is shown as 68 in the Patent Figure link above and is the actual spill port for the annuar groove in the plunger to releif the pressure to reseat the nozzle plunger separate the prime injection from the main injection events. Thus this hole provides a path for fuel to fill the HP fuel pump chamber, but a pressure releif for the spill port or split shot spit back. Do I understand how this barrel is plumbed and basically what is happening? I have other questions, but they will depend on whether I understand the operation of the injector so far. Hutch, anyone - TIA Larry |
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Is this of any help? Ken asclepius.com/carpentractor/northeastrally/ downloads1.htm |
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wkw, Sure does that's much better for my original Question 4 that what I had found - even I can understand that  Thanks Larry |
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Can anybody tell me if the injector barrel can either freely rotate or be positioned at a predetermined orientation in the nozzle housing so that the fill hole shown HERE can be oriented at any position relative to the nozzle housing and hence to the fuel rail? Also, why do they make the barrel with a common fill and relief port as shown HERE. Not being the mechanical/fluids engineer, I would think that separating these two functions within the injector barrel would make more sense and making sure that neither the fill port or relief port should be aligned with one of the fill holes in the injector housing an pointed directly out into the fuel rail. Any comments or has anyone ever thought about all of this relative to making sure the injector dymanics during it's operation make sense??? 
Larry |
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The injector barrell cone torques to 60 ft. lbs. there is no way to make the fill port orientation where you want it, once the torque is reached that's it, any tighter and damage will occur to the injector. Where did you get the drawing? Could you clarify on the chart that all the phases are actually just one injection cycle? Edited by hutchinaugusta (06/15/02 08:11 AM) |
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Hutch, If the drawing your referring to is the colored one, it was in the link that wkw gave me from the 2000 NE ralley. It's a pdf and I can't convert or annotate and post it since it's not mine. When I spoke of orientating the injector barrel in the nozzle body I was looking at THIS and couldn't tell what threaded into what, but just appeared that the barrel could be oriented so that the fill port would not align directly with the holes in the body. I'm really at a disadvantage becuase unlike you, I've never been "up close and personal" with one of these let along been able to take one apart and examine one. If you have any links to what an actual injector pieces look like or description of injector operation, those are the types of information I was hoping this thread would generate . In the past I have admitted my ignorance in the operation, but now see I must educate myself before I can see if the hypothesis I have in my mind makes any sense.Any help in pointing me to places would be much appreciated. For operation of the split shot design I mainly relied on the album on your site that has the patent info. Larry |
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Larry M It looks to me like you can not move (reindex) the barrel. If you look at your parts breakdown there are 2 dowels (DPS009) that go into the piston& valve body then align the barrell, stop plate, stop, and spacer sleeve. But I am like you and have never been able to dissect one yet. Bruce |
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KB, I see the dowels that orient the barrel all the way to the nozzle tip, and I guess the two dowel pins that go into the piston valve body also go into the barrel so everything can go together in only one orientation since from the picture of the barrel the two dowel pin holes are along a chord instead along the diameter. If this is the case then where is this port pointing when installed in the head. Is it pointed towards the fuel rail or away. My question on using the same port in the barrel for both the low pressure fill and high pressure spit back just seems strange. As the title of this thread indicates, I'm trying to understand better potential injector dynamics and understanding the physical layout and variances if one aspect. Larry |
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Larry M If you look at your breakdown picture and here you can see the body is screwed onto the piston & valve body with all the other pieces inside it. The barrell gets its fuel from inside the body. It also discharges it's split-shot, spit-back into the body. The body is sealed in the injector sleeve in the head with the rail fuel all around it between the 2 o-rings. Bruce |
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There are a couple of inaccuracies in this discussion. Kim Lux |
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What did we miss or state inaccurately? Like I said I have not been able to dissect an injector yet. I am working from pictures and parts breakdown diagrams. It is highly possible I missed something. I am not being sarcastic, please correct us on the inaccuracies. Bruce |
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Kim, Can you help in answering or pointing me to where I can find more information on my original 4 questions. If so, would you either answer here or via PM. I'm just trying to learn and educate myself. The way this barrel is designed and plumbed has me confused with its apparent common port and check valve trying to perform a dual function.  Thanks, Larry |
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TTT for any more info TIA, Larry |
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Larry, Here's a good one to ponder. RUnning under load at cruising speed I'm seeing about 1900 psi on the ICP. As I let up the throttle the icp shows a brief blip of about 1200 psi higher than cruising. The question is: How does the high pressure oil circuit alter the fuel injection if the injector can only dish out a fixed amount of fuel? Shouldn't the high pressure oil keep the same pressure regardless?? Just food for thought. |
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cmuncy, I have no idea, but to help me I just got the AutoTap for my vehicle. Is that what you are using to measure ICP and if so can you PM me any info on what types of parameters you have been getting readings on and exactly what they refer to. On my AT2 I can select Fuel pressure but it shows 0psi which makes sense since there is no fuel pressure sensor in our vehicles. I'm just learning, but it seems the documentation is sparse and learning to use this thing effectively will take a lot of OJT. Larry |
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Larry, Typically we look at fuel injection pulse width, ICP pressure, engine speed, and when doing test runs vehical speed. We take this data once logged and export it to an excel spread sheet for disection. As far as using the Autotap itself, it becomes easier to use with time. Alex Peper's scan tool on the other hand... |
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In PSD's comment that there were a couple of inaccuracies I got this not from PSD but another member and wanted to pass it on for comment: In a post it was said that the fuel enters and spits out the split-shot port. This evidently is not the case. If you go to the drawing HERE and follow through it here is what was explained to me. The fuel enters the injector from the fuel rail through the holes in the injector Body then it flows around the area outside of the Barrel and down to the Stop Plate and Stop. The Stop and Stop plate are where the inlet check valve ball is. The fuel flows through the check valve ball and up into the 'Plunger area' inside the Barrel. When the Piston is driven down by high-pressure oil, it pushes the Plunger ahead of it, pressurizing the fuel closes the inlet check ball, and through the another check ball valve in the Stop, down to the Nozzle Needle, out the Nozzle and the pre shot is injected into the cylinder. As the plunger's annular groove passes the spill port in the barrel, fuel 'leaks' out and the fuel looses pressure and injection stops. This released fuel is dumped through the spill port into the area between the barrel and the injector body again. After the plunger's groove passes the spill port the fuel pressure rises again, and the main injection is then injected into the cylinder. Also, I have received the following information from GateMan concerning my question about the orientation of the barrel in the body and the head: The spill port of the injector is at 11:00 with the injector installed in the head. This orientation is not adjustable due to location pins in the injector. The injector body holes cannot be aligned with the spill port because the injector bodies all "clock" differently when tightened to their specified torque. Even if you drilled a hole to clock with the spill port, the split shot feedback would be ejected in the opposite direction of the fuel rail. So in reality several things could be changed to make the fuel rail function better. Larry |
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cmuncy, In reply to: As a comparison I posted some data from my 1st attempt at logging various parameter on page two of my webshots site in my signature in the album titled June 22, 2002 AutoTap Data. I included plots of EOT and IAT, ICP and MGP, and ICP and FIPW. I found the ICP plots for the two 60 mph cruise control runs interesting in light of the fact that the road was fairly flat and the two data runs were within 5 min of each other. Also it seems my ICP's are quite a bit lower than what you see, but due to my engine not quite up to temp and other variables it maybe a difference w/o significance. Also since this was one of my first attempts, I am definitely still in the learning stage, but looking forward to wringing as much useful information from this tool as possible. Comments welcome since that is what this is all about - learning  Larry |
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Larry, That info I got for you was worse case. It was recorded from David Lott's race truck at WOT with huge injectors and a fat chip. I'll take a peek at what you got and see if I can see similarities. |
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Also, I found the following from one of Pat Dolan's early posts on what I understand could be the magnitude of the spill port pressures when I assume the ICP is around 3,000 HERE and hope that I have not taken it out of context: Yes, the flow pressures and volumes are extremely low, but the pulses being dampened are the spill port pressures when the split shot is being "split". Ultimately, they could be as high as 21,000 psi. These are the ones that could make the funny resonances that could cavitate the oil, possibly releasing entrained air. We don't know if this is happening, but, as Hutch has demonstrated, the potential of this system to set that condition up is significant. I believe and someone correct me if I'm wrong that this 21,000 figure is the 7 to 1 hydraulic multiplication between the oil side and the fuel side of the injector which is fixed. While looking back in the bowels of this great site I ran across THIS and note that there was talk about this angled passageway. I know this has been beat to death, but is it possible that the early heads did have such a passageway? Just some info I thought someone might be interested in Larry |
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The deeper the investigation goes the more apparent it is that the split shot injectors are "new technology" being applied to an "old fuel supply design" and just will not work well in this application, if IH had a seperate rail to dispose of the feed back fuel 99.99999% of the fuel flow issues would never have reared their ugly heads |
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Hutch, In reply to: Boy that sure is becoming painfully apparent at least to me , but we have to work with the general situation we have until someone designs and builds us new heads that we can afford   Larry |
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Does anyone have info or done something similiar to THIS. He hasn't posted here in the last 6 month's or so, but was wondering if anyone has information on what the numbers he mentioned were. I can't find any post with them, but I am still looking.
**ON EDIT, I just got thru looking for the info in the 560+ posts by this member after the date of this post and was not able to find the info. BTW it seems only 2 weeks later he was under the infamous NDA **
Also the link provide in the post by will not work, but HERE I believe is the corrected link to this reference. Hmmmmm, it seems to me that some combination of physically separating the injector body fuel cavity between the injector fill and spill port, flushing of the injector body fuel cavity back out into the fuel rail at least for the spill port area along with some fuel flow thru the rail to flush this potentially nasty fuel out of the fuel rail would be a plus.
Larry Edited by Larry M (07/06/02 07:18 AM) |
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Fuel rail geometry and injector dynamics
Re: Fuel rail geometry and injector dynamics
